Lung cancer is the primary cause of cancer death among both men and women in the U.S., with an estimated 172,000 new cases being reported in 1994. The five-year survival rate among all lung cancer patients, regardless of the stage of disease at diagnosis, is only 13%. This contrasts with a five-year survival rate of 46% among cases detected while the disease is still localized. However, only 16% of lung cancers are discovered before the disease has spread. Lung cancers are broadly classified into small cell or non-small cell lung cancers. Non-small cell lung cancers are further divided into adenocarcinomas, bronchoalveolar-alveolar, squamous cell and large cell carcinomas. Approximately, 75-85 percent of lung cancers are non-small cell cancers and 15-25 percent are small cell cancers of the lung.
Early detection is difficult since clinical symptoms are often not seen until the disease has reached an advanced stage. Currently, diagnosis is aided by the use of chest x-rays, analysis of the type of cells contained in sputum and fiberoptic examination of the bronchial passages. Treatment regimens are determined by the type and stage of the cancer, and include surgery, radiation therapy and/or chemotherapy.
Early detection of primary, metastatic, and recurrent disease can significantly impact the prognosis of individuals suffering from lung cancer. Non-small cell lung cancer diagnosed at an early stage has a significantly better outcome than that diagnosed at more advanced stages. Similarly, early diagnosis of small cell lung cancer potentially has a better prognosis.
Although current radiotherapeutic agents, chemotherapeutic agents and biological toxins are potent cytotoxins, they do not discriminate between normal and malignant cells, producing adverse effects and dose-limiting toxicities. There remains a need for lung cancer specific cancer markers. There remains a need for reagents and kits which can be used to detect the presence of lung cancer markers in samples from patients. There remains a need for methods of screening and diagnosing individuals who have lung cancer and methods of monitoring response to treatment, disease progression and disease recurrence in patients diagnosed with lung cancer. There remains a need for reagents, kits and methods for determining the type of lung cancer that an individual who has lung cancer has. There remains a need for compositions which can specifically target lung cancer cells. There remains a need for imaging agents which can specifically bind to lung cancer cells. There remains a need for improved methods of imaging lung cancer cells. There remains a need for therapeutic agents which can specifically bind to lung cancer cells. There remains a need for improved methods of treating individuals who are suspected of suffering from lung cancer.